CHARLOTTE, NC -- Mitt Romney delivered a blistering attack on President Obama's economic record just footsteps from the site where the president will accept his re-election nomination this summer.

On a rooftop a few hundred yards away from the Bank of America stadium, Romney offered his own alternative version of what North Carolinians could expect to hear from the president in his acceptance speech, as well as what they would not.

"What you won’t hear at that convention is that for the last 38 months, unemployment has been above 8 percent, that we’ve had 24 million Americans that are out of work, stopped looking for work, or underemployed," Romney said.

"You won’t hear that, since he gave that speech and became president, that there have been 50,000 more job losses here in North Carolina, more than twice as many as would fit in that stadium," Romney continued, referring to the nearby stadium, the home of the NFL's Carolina Panthers, where the president will speak on the final night of the Democratic convention.

The empty stadium was meant to serve as the backdrop for Romney's speech today -- a visual bracketing of the president -- but was ultimately thwarted by rain that forced the remarks indoors.

Romney focused not just on Obama's planned 2012 convention speech, but also his 2008 remarks, reading aloud from a portion at one point and substituting then nominee-Obama's rebuke of the Bush economy, with his own criticism for the Obama economy, urging the president to take ownership of the economy.

"He can’t continue to try and deflect blame elsewhere," Romney said. "At some point he’s got to acknowledge this is his economy –- that what’s happened is the result of his policies –- not of his predecessors, not of Congress."

He even cracked a joke at the expense of the optics of Obama's acceptance speech, in which the president stood amidst towering Greek columns on the floor of Denver's Invesco field.

"You're not going to see President Obama standing alongside Greek columns. He's not going to want to remind anybody of Greece," Romney said.

The former Massachusetts governor also said the economy may yet improve before Election Day, but that the president would deserve no credit if it did so.

"Upon being elected president he said if we let him borrow $787 billion he would hold unemployment below eight percent, and it has not been below eight percent since," Romney said. "Now its going to get below 8 percent someday. Our economy always come back, comes back -- but it's no thanks to the policies of Barack Obama."

The presumptive GOP nominee also predicted that, despite the presence of the Democratic convention in the state, and the president's current organizational edge here, Romney would return the Tarheel State to the Republican column in 2012.

"The president’s going to do everything he can to get North Carolina in his column, and that will not be enough because we’re gonna win North Carolina in November," Romney said, to cheers.

In a nod to recent polling that continues to show Obama's personal favorability ratings greatly outpacing his own, Romney also argued that liking the president alone was not reason enough to vote for him.

"Even if you like Barack Obama, we can't afford Barack Obama," Romney said.